Certifications

Selected Publications

Research Summary

Dr. Loeb has active laboratory and clinical research efforts. In the laboratory, Dr. Loeb studies a gene called WT1. High levels of WT1 convey a poor prognosis for patients with osteosarcoma and soft tissue sarcomas. Dr. Loebs laboratory has shown that WT1 expression is regulated, in part, by the amount of oxygen in a tumor, and that low oxygen levels lead to higher WT1 expression, which in turn leads to an increase in the ability of tumor cells to cause new blood vessels to form. The laboratory is studying both the mechanism by which oxygen levels control WT1 expression and the way WT1 regulates blood vessel growth. In a related project, Dr. Loebs laboratory is working to identify, characterize, and therapeutically target Ewing sarcoma stem cells. Cancer stem cells are thought to be inherently resistant to chemotherapy and are thought to cause most cases of refractory or relapsed disease. In collaboration with the laboratory of Dr. Jonathan Powell, Dr. Loeb has identified one pathway, called the mTOR signaling pathway, that may be important for sarcoma stem cells to resist chemotherapy. This finding prompted the initiation of a clinical trial, led by Dr. Loeb, to test the combination of Doxil, a standard chemotherapy drug, and Temsirolimus, an inhibitor of the mTOR signaling pathway, in patients with high risk sarcomas. Future clinical trials, already being planned, will test additional means by which the inherent chemoresistance of these key cells can be overcome, hopefully leading to significant improvements in the survival of patients with recurrent or refractory sarcomas.